Comparison of their clinical phenotypes has established some genotype-phenotype correlations and has identified three genes, preferentially expressed in the brain and located in a genomic region spanning 1.36 Mb (between the hg19 genomic coordinates 243,663,021 and 245,027,827), as the main genes contributing to the 1qter microdeletion phenotype: AKT3 is the main candidate for microcephaly, ZBTB18 for AnCC and HNRNPU for epilepsy (Ballif et al. 2012; Nagamani et al. 2012; Thierry et al. 2012). The gene discussed is AKT3; the disease is microcephaly.